Styjun

Im creating an app that shows different locations. Currently when a button is pressed the car locations pop up on the map, however I want to then hide those shown markers if that same button is pressed again.

This is the function that takes a snapshot of my database from firebase, it then inserts the GMSMarker into the location.

 func showCarIcon() 

 ref = Database.database().reference()

 ref.child("location").observe(.childAdded) (snapshot:DataSnapshot) in
 if let dict = snapshot.value as? [String:AnyObject] 
 if dict["Activity"] as! String == "Car" 
 let longitude = dict["Longitude"] as! String
 let lattitude = dict["Lattitude"] as! String
 let title = dict["Title"] as! String
 self.carIconArray.insert(coordinate(carLat: lattitude, carLng: longitude), at: 0)
 let n = self.carIconArray.count
 let heightWidth = self.mapView.frame.height
 for marker in 1...n 
 let carMarker = GMSMarker()
 let carIconView = UIImage(named: "carPin")
 let image = carIconView
 let location = CLLocationCoordinate2D(latitude: Double(lattitude)!, longitude: Double(longitude)!)
 carMarker.position = location
 carMarker.icon = image
 carMarker.title = title
 carMarker.icon = self.image(image!, scaledToSize: CGSize(width: heightWidth/6, height: heightWidth/6))
 func displayIt() 
 if self.carNumber == "1" 
 carMarker.map = self.mapView
 else 
 carMarker.map = nil
 
 

 displayIt()
 
 
 
 

So this is the action function for when button is pressed.

var carNumber = String()

@IBAction func showCar(_ sender: Any) 
 if motorisedVehicleButtonActive 
 motorisedVehicleButton.setImage(UIImage(named: "carO"), for: .normal)
 carNumber = "1"
 else 
 motorisedVehicleButton.setImage(UIImage(named: "car"), for: .normal)
 carNumber = "0"
 
 print(carNumber)
 motorisedVehicleButtonActive = !motorisedVehicleButtonActive
 showCarIcon()

Let me explain what is issue with your code.

1. You are creating new marker every time when button press. So, new marker have different object id than older.




2. When you try to remove it, it will not works just because of it's different marker than you placed on map.




3. So you need to store marker in array and on remove time, get icon from array and remove it from map.

First you need to create array of GMSMarker, because you have to store every marker which is placed on map.

So, write following line of code at top of your class.

var arrCarMarkers = [GMSMarker]()

Then after, store every marker in this array which are you placing on map.

So, update your code as follow:

func displayIt() 
 if self.carNumber == "1" 
 carMarker.map = self.mapView
 arrCarMarkers.append(carMarker) // Here is store marker in array
 else 
 carMarker.map = nil
 

Now, you have all marker which are placed on map. So when you want to remove these markers just update your code as follow:

@IBAction func showCar(_ sender: Any) 
 if motorisedVehicleButtonActive 
 motorisedVehicleButton.setImage(UIImage(named: "carO"), for: .normal)
 carNumber = "1"
 showCarIcon()
 else 
 motorisedVehicleButton.setImage(UIImage(named: "car"), for: .normal)
 carNumber = "0"
 self.arrCarMarkers.forEach $0.map = nil 
 
 print(carNumber)
 motorisedVehicleButtonActive = !motorisedVehicleButtonActive

Above code will remove all markers from map.

I hope this will works for you.